黑土区小流域土壤速效磷空间分布模拟方法

为探索东北黑土小流域土壤AP空间分布模拟的最佳方法,综合考虑区域尺度、景观格局和采样方法等信息,选取两个典型黑土小流域(光荣和海沟河流域)作为研究对象,结合半变异分析、回归分析、主成分分析等方法,比较了不同空间插值方法(反距离权重法、径向基函数法、普通克里格、协同克里格、多元线性回归模型、地理加权回归模型、回归克里格和地理加权回归克里格)对AP空间模拟精度的影响。结果表明:(1)引入主成分分析后能够提高回归克里格和地理加权回归克里格方法的模拟精度(4.5%和2.4%);(2)地理加权回归克里格方法可以作为最优空间插值方法模拟黑土区小流域AP的空间分布格局。地理加权回归克里格方法相较于传统插值方法能在一定程度上提高黑土小流域土壤AP空间模拟精度,为小流域尺度黑土养分管理提供技术支撑。

Comparing Interpolation Methods to Predict the Spatial Distribution of Soil Available Phosphorus in the Mollisol Watershed of Northeast China

To explore the optimal method of simulating the spatial pattern of available phosphorus(AP)in Mollisol watershed of Northeast China,semi-variance analysis,regression analysis and principal component analysis were combined,and eight interpolation methods including inverse distance weighted(IDW),radial basis functions(RBF),ordinary Kriging(OK),co-Kriging(COK),multiple linear regression(MLR),geographically weighted regression(GWR),regression Kriging(RK),and geographically weighted regression Kriging(GWRK)were used to simulate the spatial patterns of soil AP in two typical Mollisol watershed(Guangrong watershed and Haigouhe watershed)with different kinds of landscapes at diverse scales.The results show that:(1)the introduction of PCA can improve the prediction accuracy of RK method(4.5%increment)and GWRK method(2.4%increment);(2)GWRK method can be used as the optimal interpolation method to simulate the spatial distribution pattern of soil AP in Mollisol watershed compared with the traditional interpolation method,GWRK can improve the simulation accuracy of soil AP in Mollisol watershed and provide technical support for nutrient management.